
==== Front
Cureus
Cureus
2168-8184
Cureus
2168-8184
Cureus Palo Alto (CA)

10.7759/cureus.67077
Dermatology
Pityriasis Rubra Pilaris in an Atopic Dermatitis Patient: A Case Report
Muacevic Alexander
Adler John R
Almoqati Mehad 1
Almasoudi Lama 2
Alfaqih Zainab 2
Fageeh Sarah M 3
Al Hawsawi Khalid 3
1 College of Medicine, Taif University, Taif, SAU
2 Faculty of Medicine, Umm Al-Qura University, Makkah, SAU
3 Dermatology, King Abdulaziz Hospital, Makkah, SAU
Khalid Al Hawsawi hawsawik2002@hotmail.com
17 8 2024
8 2024
16 8 e6707717 8 2024
Copyright © 2024, Almoqati et al.
2024
Almoqati et al.
https://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License CC-BY 4.0., which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
This article is available from https://www.cureus.com/articles/272322-pityriasis-rubra-pilaris-in-an-atopic-dermatitis-patient-a-case-report
Pityriasis rubra pilaris (PRP) is a rare, chronic, inflammatory papulosquamous skin disease. Here, we report a case of a 43-year-old female with a known history of atopic dermatitis, bronchiectasis, and goiter who presented with a six-month history of persistent itchy skin lesions on her extremities. A skin examination revealed multiple diffuse, well-defined, fine, scaly erythematous patches with areas of spared skin over all four extremities, along with palmoplantar keratoderma. The trunk was spared. The differential diagnosis included atopic eczema, pityriasis rubra pilaris, dermatomyositis, mycosis fungoides, parapsoriasis, psoriasis, and drug-induced eczematous dermatitis. A skin biopsy revealed hyperkeratosis, acanthosis, spongiosis, follicular plugging, and mild perivascular lymphohistiocytic cellular infiltrates in the dermis. Based on the clinicopathological findings, the patient was diagnosed with atypical adult pityriasis rubra pilaris (PRP) (type II). She was started on narrowband UVB phototherapy (NBUVB). Two months after starting NBUVB treatment, all the skin lesions had cleared. She was put under periodic follow-up, and the lesions have remained clear for two years up to the time of this publication.

atopic dermatitis
nbuvb
ppk
type ii prp
prp
atypical adult pityriasis rubra pilaris
Third party editing professional services were received for this case report from Scribbr.
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pmcIntroduction

Pityriasis rubra pilaris (PRP) is an uncommon inflammatory papulosquamous condition affecting both adults and children. Six distinct types of PRP have been identified based on clinical characteristics, age of onset, and prognosis. The etiology is unknown. The disease’s pathophysiology includes impaired immune function, poor keratinization, abnormal vitamin A metabolism, and CARD14 mutations. Triggering factors include infection, ultraviolet exposure, minor traumas, and drugs [1-5]. PRP is characterized by erythematous scaly patches with areas of spared skin, follicular hyperkeratosis on an erythematous base, and yellowish palmoplantar keratoderma (PPK) [6]. The lesions usually start on the head and neck and spread downward to the body [7]. Type II PRP, also known as atypical adult PRP, affects 5% of all PRP cases [8]. It is characterized by ichthyosiform scales, PPK with coarse lamellated scales, and occasionally alopecia [9]. Here, we report a case of a 43-year-old female with a known history of atopic dermatitis, bronchiectasis, and goiter, who was diagnosed with atypical adult PRP (type II).

Case presentation

A 43-year-old female presented to our clinic with a 6-month history of persistent itchy skin lesions on her extremities. The skin lesions started on the upper extremities, including the palms, and then spread down to the lower extremities, including the soles. She had mild atopic dermatitis on her upper extremities that was well-managed with a topical steroid. Unlike her chronic atopic dermatitis, the new rash did not respond to treatment with medium potency topical steroid (MPTS) as betamethasone valerate. Moreover, the patient had been diagnosed with bronchiectasis and was on albuterol and periodic IV antibiotics. She also had a goiter, which was under observation without active intervention. There were no similar cases in her family. A skin examination showed multiple, well-demarcated, fine, scaly erythematous patches with areas of spared skin on all four extremities associated with palmoplantar keratoderma (Figure 1). The differential diagnosis included atopic eczema, pityriasis rubra pilaris, dermatomyositis, mycosis fungoides, parapsoriasis, psoriasis, and drug-induced eczematous dermatitis. A skin biopsy was taken, which revealed mild hyperkeratosis, acanthosis, spongiosis, follicular plugging, and mild perivascular lymphohistiocytic cellular infiltrates in the dermis (Figure 2). The laboratory workup was normal for complete blood count (CBC), muscle enzymes, liver enzymes, serum urea, and creatinine. Based on the above clinicopathological findings, the patient was diagnosed with atypical adult pityriasis rubra pilaris (PRP) (type II). She was started on narrowband ultraviolet B phototherapy (NBUVB). Following two months of NBUVB treatment, complete resolution of all skin lesions was observed (Figure 3). Subsequently, the patient was subjected to periodic follow-up, and the lesions have remained in remission for two years up to the time of this publication.

Figure 1 Multiple, diffuse, well-defined, fine, scaly erythematous patches with an area of spared skin on (A) upper extremities, (B) lower extremities, and (C) palmoplantar keratoderma

Figure 2 Mild hyperkeratosis, acanthosis, spongiosis, follicular plugging, and mild perivascular lymphohistiocytic cellular infiltrates in the dermis

Figure 3 Complete resolution after two months of starting NBUVB therapy: (A) upper extremities, (B) lower extremities

NBUVB: narrowband ultraviolet B phototherapy

Discussion

PRP is a rare, inflammatory, papulosquamous dermatological disorder [1]. The spectrum of PRP variants is categorized into six distinct subtypes, including classic adult PRP, atypical adult PRP, classic juvenile PRP, circumscribed juvenile PRP, atypical juvenile PRP, and human immunodeficiency PRP [2]. A PRP diagnosis can be difficult to make due to the presence of similar conditions, including atopic eczema, dermatomyositis (DM), mycosis fungoides (MF), parapsoriasis, psoriasis, and drug-induced eczematous dermatitis [10]. Although the skin biopsy results in this case were nonspecific, as can be seen in atopic dermatitis and partially treated PRP as seen in our case, as she received topical corticosteroid. However, the well-demarcated skin lesion borders seen in our patient are against atopic dermatitis. Also, there were no features suggestive of DM (Wong type), MF, or psoriasis. The atypical acral localization of the skin lesions added more complexity to the diagnosis of PRP. The typical persistent, fine, scaly, well-defined erythematous patches with islands of normal skin and the ichthyosiform scales and the patient’s rapid response to NBUVB therapy suggested a diagnosis of PRP. Massa A et al. present a case of an eight-year-old girl with mixed type III/IV PRP who showed 90% improvement after two months of initiating NBUVB treatment [11]. Another study reported treatments for PRP, including systemic isotretinoin, acitretin, phototherapy, and systemic immunosuppressants either alone or in combination [12].

Conclusions

Our case underscores the diagnostic challenges of PRP, especially with its atypical presentations and overlapping characteristics with other dermatological conditions such as atopic eczema. Despite nonspecific biopsy results, the persistent scaly erythematous patches with islands of normal skin and ichthyosiform scales, and rapid improvement with NBUVB therapy pointed toward PRP. This case emphasizes the need to consider PRP in the differential diagnosis of papulosquamous disorders to ensure effective management and improved patient outcomes.

Disclosures

Author Contributions

Human subjects: Consent was obtained or waived by all participants in this study.

Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following:

Payment/services info: Third party editing professional services were received for this case report from Scribbr.

Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work.

Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work.

Concept and design:  Mehad Almoqati, Lama Almasoudi, Zainab Alfaqih , Sarah M. Fageeh, Khalid Al Hawsawi

Drafting of the manuscript:  Mehad Almoqati, Zainab Alfaqih , Khalid Al Hawsawi

Critical review of the manuscript for important intellectual content:  Mehad Almoqati, Lama Almasoudi, Sarah M. Fageeh

Acquisition, analysis, or interpretation of data:  Lama Almasoudi, Zainab Alfaqih , Sarah M. Fageeh, Khalid Al Hawsawi

Supervision:  Khalid Al Hawsawi
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References

1 Pityriasis rubra pilaris: algorithms for diagnosis and treatment J Eur Acad Dermatol Venereol Roenneberg S Biedermann T 889 898 32 2018 29247481
2 Pityriasis rubra pilaris JAMA Dermatol Eastham AB 404 155 2019 30725099
3 Pityriasis rubra pilaris: a study evaluating patient quality of life in 2 populations J Am Acad Dermatol Eastham AB Tkachenko EY Femia AN 638 640 81 2019 30710600
4 The management and genetic background of pityriasis rubra pilaris: a single-centre experience J Eur Acad Dermatol Venereol Gál B Göblös A Danis J 944 949 33 2019 30697821
5 Pityriasis rubra pilaris: an updated review of clinical presentation, etiopathogenesis, and treatment options Am J Clin Dermatol Joshi TP Duvic M 243 259 25 2024 38159213
6 Successful treatment of type II pityriasis rubra pilaris with secukinumab JAAD Case Rep Gauci ML Jachiet M Gottlieb J 462 464 2 2016 27981219
7 Updates on pityriasis rubra pilaris: a scoping review J Cutan Med Surg Zhou T Al Muqrin A Abu-Hilal M 158 166 28 2024 38174859
8 Pityriasis rubra pilaris (PRP): a case report of type II Medical science Rajeh MS Al -Gethami MA Al Hawsawi KA Alsehly LM Al Hawsawi KA 686 690 24 2020 https://discoveryjournals.org/medicalscience/current_issue/v24/n102/A33.htm
9 A review on pityriasis rubra pilaris Am J Clin Dermatol Wang D Chong VC Chong WS Oon HH 377 390 19 2018 29302927
10 Clinical course, diagnostic patterns, and treatment outcomes in patients with pityriasis rubra pilaris J Am Acad Dermatol Ji-Xu A Lei DK Maloney NJ Worswick S 1450 1451 87 2022 35931219
11 Pityriasis rubra pilaris mixed type III/IV successfully treated with narrow band-ultraviolet B Indian J Dermatol Venereol Leprol Massa AF Vasconcelos P Soares de Almeida L Filipe P 435 81 2015
12 Pityriasis rubra pilaris treated with acitretin and narrow-band ultraviolet B (Re-TL-01) Br J Dermatol Kirby B Watson R 376 377 142 2000 10730782
